Selective right middle and lower lobar blockade for minimally invasive cardiac surgery: a prospective, single-center, randomized controlled study

BACKGROUND: Minimally invasive cardiac surgery (MICS) is increasingly performed due to faster recovery time and lower postoperative complications when compared with the traditional open surgery. However, hypoxemia in lung isolation duration after cardiopulmonary bypass (CPB) surgery has been the focus of anesthesiologists’ attention. In the present study, we designed a novel lung isolation strategy to improve oxygenation using a bronchial blocker (BB) to isolate the right middle and lower lobes and preserve the ventilated right upper lobe without affecting the surgical field. METHODS: Patients who had undergone right lateral mini-thoracotomy, a MICS, between August 2018 and February 2019, were enrolled in this randomized controlled study. Patients were randomly divided into a modified lung isolation group (group M) and a conventional lung isolation group (group C). In group M, BBs were used to block the bronchus intermedius, while left-sided double lumen endotracheal tubes were used in group C to isolate the right lung. The primary outcome was to determine the number of patients who required an increase in ventilation volume due to hypoxemia during lung isolation after CPB. RESULTS: Sixty-one patients (30 in group C and 31 in group M) were enrolled. Five patients in group M were converted to right lung isolation due to poor surgical field exposure. During lung isolation after CPB, the number of patients with hypoxemia was lower in group M than group C (5/31 vs. 15/30, P=0.005). CONCLUSIONS: The novel modified lung isolation strategy reduced the incidence of hypoxemia after CPB.